Nano-fabrication involves the fabrication of very small structures, e.g., having features on the order of 100 nanometers or smaller. One area in which nano-fabrication has had a sizeable impact is in the processing of integrated circuits. As the semiconductor processing industry continues to strive for larger production yields while increasing the circuits per unit area formed on a substrate, nano-fabrication becomes increasingly important. Nano-fabrication provides greater process control while allowing increased reduction of the minimum feature dimension of the structures formed. Other areas of development in which nano-fabrication has been employed include biotechnology, optical technology, energy systems and the like.
An exemplary nano-fabrication technique is referred to as imprint lithography. Exemplary imprint lithography processes are described in detail in numerous publications, such as U.S. patent application publication 2004/0065976, U.S. patent application publication 2004/0065252, and U.S. Pat. No. 6,936,194, all of which are assigned to an assignee of the present invention.
An imprint lithography technique disclosed in each of the aforementioned U.S. patent application publications and U.S. patent includes formation of a relief pattern in a formable liquid (polymerizable layer) and transferring a pattern corresponding to the relief pattern into an underlying substrate. The substrate may be positioned upon a motion stage to obtain a desired position to facilitate patterning thereof. To that end, a template is employed spaced-apart from the substrate with a formable liquid present between the template and the substrate. The liquid is solidified to form a solidified layer that has a pattern recorded therein that is conforming to a shape of the surface of the template in contact with the liquid. The template is then separated from the solidified layer such that the template and the substrate are spaced-apart. The substrate and the solidified layer are then subjected to processes to transfer, into the substrate, a relief image that corresponds to the pattern in the solidified layer.
Many nano-patterning applications take advantage of the size and uniform shape of nano-scale features to achieve a desired result. Many processes employed to make nano-patterns use a bottom-up “growth” process to grow a particular type and size of nano-patterns based on chemistry. Unfortunately, these types of processes may be slow and prone to producing nano-patterns whose size and shape may be insufficiently controlled to produce desired performance cost effectively. Thus there remains a need for processes that provide for better control of the processed sizes and shapes of nano-scale structures.